Method of making ornamented rubber articles



May 21, 1935.

A. L. DILLER ET AL METHOD OF MAKING ORNAMENTED lRUBBER ARTICLES Filed Feb. 27, 1934 Q EJ# MANY@- iff 5- Patented May 21, 1935 ME'rnon or MAKING ORNAMENTED RUBBER ARTICLES Alvin L. Diller, Belmont, and Leslie H. LHollier,

Waltham, Mass., assignors to `Hood Rubber Company, Inc., Watertown, Mass., acorporaf tion of Delaware v ApplieationFebruary 27, 1934, Serial No. 713,167

` 4 claims. (el. ls-ss) This invention relates to the manufactureoi ornamented rubber articles and, especially to the production of rubber articles with both variegated and configured surfaces.

The chief objects ofthe invention are to pro'- vide an attractively Vornarnented 'article and to provide convenient procedure for producing the same. A more pspeciiic `object is ,toV utilize to specialadvantage the phenomenon of surface tension of liquids in the production of ornamentation.

These and further objects will be apparent from the following description, reference being had to the accompanying drawing in which:

Fig. lis a vertical section of `a dipping tank witha footwear form suspended therein and utilized in accordance with the preferred procedure of the invention.

Fig. 2. is an elevation ,of the form of Fig. 1 `having ornamenting material deposited thereon. Fig. 3 is an enlarged section taken along the line 3-3 of Fig. 2. Y

Fig. 4 is a still greater enlargement, with'parts broken away, of the form and ornamenting material of Fig. 3 having a layer of rubber of the nal article deposited upon the same.

Fig. 5 is an elevation of a lasted, ornamented rubber shoe constructed according to and embodying the invention in its preferred form.

Figs. 6 and '7 are views simil-ar to Figs. 3 and 4, respectively, but illustrating a modiiication in the manner of carrying out the invention, effective to produce a different ornamental eiect.

Fig. 8 is a View similar to Fig. 5 but showing a shoe with the modied ornamentation obtained in accord-ance with Figs. 6 and '7.

In the preferred manner of carrying out the invention, the production of a rubber shoe being chosen for illustration, a form I0 is provided having an embossed surface such that it has miniature hills Il, II and valleys I 2, I2 in the desired design, for example, thatof a reptile skin. The form may be constructed by covering a rigid support I3 with a socklike structure I4 of sheet material, such as leather or rubber, having the desired embossed surface, the sock being closed at its open end by a binding tape I5. For the sake of economy of space, and to provide'certain advantages hereinafter more fully discussed, the form may be of the flat shape shown, the dimensions of which, however, are such as to permit subsequent shaping of a layer of rubber moldedupon it to the nal shoe shape without objectionable stretching of such layer.

The form is coated'with a liquid-dispersed persion to settle in an ornamenting arrange'- ornamenting material of the desii'edtcolor, as by ment. Prior to depositing the ornamenting dispersion, the form surface maybe wetted` with a liquid, as by dipping the formin water, to avoid the trapping of, air next to the form surf' face.

The dispersion remaining on the `form accom# modates itself to the embossed surface thereof, under the inuences of gravity and of the surface tension of the liquid, and if the dispersion is of such fluidity that gravity is not entirely overcome by surface tension, the dispersion in each valley willtake the form of a sagging menisrcus with the thickest portion of the'A deposit 1ocated at or near the lowermost portion of the valley, which, in the suspended position of the form will be at the lowermost hillside of each valley, and with a gradual diminishing thickness of the deposit upwardly toward the other side of the valley as shown at I1, I1 in Figs. 2, 3 and 4. According to whether the liquid of the dispersion is such as to wet the surface of the form easily or poorly, the film in some cases will be continuous over the crests of the hills, although very thin in those regions, or it Y may become separated at the hills and gather in small puddles in the valleys.

The deposited dispersion is then permitted to dry, at least'partially, upon the form, and a layer I8 of rubber providing the body of the article and a backing for the deposits of a diierent color or shade than the deposits is molded against the form and deposits thereon, preferably by dipping the latter in an aqueous dispersion of the rubber with the aid of a coagulant to effect the deposition, and drying the deposit.

Thelayer of rubber I8 with the ornamenting deposits Il, I1 adhering thereto is then removed from the form and mounted inside out upon a shaping last I9 in association with such other shoe parts as may be desired, such as an insole, outsole, heel and lining, and the whole then vulcanized on the last.

In the surface of the final article the ornamenting deposits appear chieily at the side por-k tions of the ridges corresponding to the lower hillsides of the form, the remaining portions of the surface showing the color of the base layer I8 of the article. The effect of the ornamentation is to emphasize the conguration of the surface and, in the case of reproducing the surface of leather, to enhance the similarity of its appearance to real leather.` y

By the use of the flat form shown, rather than one with curved sides, a greater uniformity of distribution of the ornamenting material-over each side surface is obtained, the draining being very nearly the same as to all of the depressions.

It is preferred to use an aqueous dispersion of rubber containing the desired coloring agent for the ornamenting material. Good results have been obtained with the use or" latex diluted and pigmented sol that the dispersion into which the form is dipped comprises about eight to fteen percent by Weight of solid matter, the rest being liquid. The proportion of solid matter is governed to some extent according to Whether a deep or pale shade of the color is desired.

Byv materially decreasing the liquidity of the ornamenting dispersion a diiferent effect may be producedas illustrated in the modification of Y Figs. 6, 'l and 8.

In this procedure the form is dipped and allowed to drain and dry as in the procedure described for Figs. l to 5, but a dispersion is used of such viscosity that it does not flow as readily and remains predominantly in the bottoms of the valleys in the surface of the form, as shown at 20, 2,0', the eiect of surface tension on the liquid, however, being sufficient to cause the deposit to be exceedingly thin or broken at the hillsides and crests of the form.

. After the layer of body rubber 2i has been deposited upon the form and stripped off, the

ornamenting deposits'appear upon it chiefly at 'the tops of the configuration, the depressions between, corresponding rto the crests of the form, showing thecolor of the rubber 2|, as shown at 22 in Fig.'8.

Good results for this manner of ornamentation have been obtained by the use of an ornamenting dispersion containing about one-half by Weight of solid matter.

We claim:

1. The method of making an ornamented rubber article which comprises providing a negative form configured with miniature valleys and hillsides in its surface, depositing on said form an ornamenting dispersion of such fluidity and 10W content of coloring matter that, after draining and at least partially drying, the residue of the deposit appears in areas of relatively deep hue merging With areas of fainter hue, permitting the deposited dispersion thus to drain and dry, then depositing upon the form a layer of rubber and removing the latter to provide a positive of the surface conguration with the ornamenting depositsV adhered to its surface and With its surface color appearing between the areas of deepest hue of the deposits.

2. A method as defined in claim l in which the form is so suspended during the draining and drying that the Valleys are defined by upper and lower hillsides and the deposited ornamenting Ydispersion is of such fluidity that the lower one of the hillsides of each valley receives the deepest hue of thedeposit.

3. A method as deined in claim 1 in which the deposited ornamenting material is of such small degree of fluidity that thebottom of each valley receives the deepest hue of the ornamenting deposit merging into a fainter hue at the hillsides of the Valley.

4. A method as defined in claim l in which the form is of a generally iiat shape and the ornamented rubber article formed upon it is subsequently shaped upon a support.

ALVIN L. DILLER. LESLIE H. LHOLLIER. 

